/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.lealone.common.util;

import java.util.HashSet;

public class ShutdownHookUtils {

    private static final HashSet<Thread> hooks = new HashSet<>();

    public static synchronized void addShutdownHook(Object object, Runnable hook) {
        String hookName = object.getClass().getSimpleName() + "-ShutdownHook-" + hooks.size();
        addShutdownHook(hookName, hook, false);
    }

    public static synchronized void addShutdownHook(String hookName, Runnable hook) {
        addShutdownHook(hookName, hook, true);
    }

    public static synchronized void addShutdownHook(String hookName, Runnable hook, boolean addPostfix) {
        if (addPostfix)
            hookName += "-ShutdownHook";
        Thread t = new Thread(hook, hookName);
        addShutdownHook(t);
    }

    public static synchronized void addShutdownHook(Thread hook) {
        hooks.add(hook);
        Runtime.getRuntime().addShutdownHook(hook);
    }

    public static synchronized void removeShutdownHook(Thread hook) {
        hooks.remove(hook);
        Runtime.getRuntime().removeShutdownHook(hook);
    }

    public static synchronized void removeAllShutdownHooks() {
        for (Thread hook : hooks) {
            Runtime.getRuntime().removeShutdownHook(hook);
        }
        hooks.clear();
    }
}
